Kurzer 2 1,2,3-Thiadiazoles

The use of infrared (IR) as a technique for structure determination is not very common in recent times. The reviews by Kurzer <1965AHC(5)119, 1982AHC285> contain a table of IR spectral absorptions of 1,2,4-thiadiazoles which covers spectra published before 1982. Additional spectral data was published in CHEC(1984) <1984CHEC(6)463>. 

The fifth volume of Advances in Heterocyclic Chemistry surveys the chemistry of four well-defined groups of compounds pyrrolizidines (N. K. Kochetkov and A. M. Likhosherstov), aromatic quinolizines (B. S. Thyagarajan), 1,2,4-thiadiazoles (F. Kurzer), and the amino-chrome pigments (R. A. Heacock). 

The preparations of 1,2,4-thiadiazoles and 1,2,4-thiadiazolidines from thioureas are well known and have been summarized in three reviews those of Bambas,188 Sherman,189 and Kurzer.170 Contained in these reviews are discussions of the controversies that surrounded some of the products, notably Hector s bases, which resulted from oxidation of substituted thioureas.171,172 Subjects covered in the above reviews, but too extensive to outline in detail here, are the oxidation of amidinothioureas to 3,5-diamino-1,2,4-thiadiazoles (71),173,174 the oxidation of phenylthiourea175 and of substituted amidinothioureas176 to 3,5-diimino-l,2,4-thiadiazolidines (72, Hector s bases), the reaction of thiopseudoureas with trichloromethanesulfenyl chloride to form 3-alkylthio-5-chloro-l,2,4-thiadiazoles (73),177 the reaction of thiopseudoureas with sodium thiocyanate and bromine178 and the oxidation... 

In this chapter the extensive review on 1,2,4-thiadiazoles by Kurzer (65AHC(5)ll9) was utilized for information published prior to 1965. For the period 1965-1981, many literature references were obtained by computer methods and from short heterocyclic reviews (B-79MI42501, B-79MI42502, 77SST(4)422>. 

Vibrational assignments for IR spectral absorptions of thiadiazoles were made by Rao and Venkataraghavan (64CJC43). Spectra published until 1965 are tabulated in a review by Kurzer (65AHC(5)119) and data since 1965 are listed in Table 1. 

The purpose of this chapter is to review the organic and physical chemistry of monocyclic 1,2,5-thiadiazoles up to the early part of 1967. Reference is made to the 2,1,3-benzothiadiazoles and related compounds only as they contribute to the chemistry of the basic ring system. The four isomeric thiadiazoles, including their benzo derivatives, were previously reviewed by Bambas, Grignard, and Sherman and the chemistry of 1,2,4-thiadiazoles was reviewed by Kurzer. ... 

By cyclizing thiosemicarbazide with iV,iV -diphenylcarbodiimide, Goodfrey and Kurzer obtained 2-amino-5-anilino-l,3,4-thiadiazole (57) with the thiocarbamidoaminoguanidine (56) as intermediate. 57 and similar compounds (59), also with alkylamino groups, have... 

Volume 32 consists of five chapters. Of these, that by Kurzer on 1,2,4-Thiadiazoles updates his own contribution on this subject which appeared in 1965 in Volume 5. 

A soln. of 4-phenyl-l-(thiobenzoyl)semicarbazide in coned. HCl-ethanol refluxed 15 min. 2-hydroxy-5-phenyl-l,3,4-thiadiazole. Y 95%. F. e. s. F. Kurzer, Soc. 1961,1617. 

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